Coating apparatus



May l, 1934. F, CQATES 1,956,561

COATING APPARATUS Filed July l5, 1930 fg@ z ATTORNEYS.

Patented May 1, 1934 SIAES COATING APPARATUS Robert M. Coates Application July 15, 1930, Serial No. 468,042

Claims.

This invention relates to web coating apparatus and has special reference to a spreader for web coating machines designed to spread the coating evenly and smoothly over the web on which it has been deposited.

One important object of the invention is to provide an improved spreader wherein the spreading of a coating on a web will be accomplished by elastic means capable of being adlo usted with great readiness to obtain the desired pressure.

A second important object of the invention is to provide in a machine of this character an improvec. form of distributing device.

A third important object of the invention is to provide an improved spreader wherein one spreading element will be in the form or a pneumatic tube.

A fourth important object of the invention is to provide an improved spreader of this class wherein the pneumatic tube will be so mounted as to be capable of expansion substantially in one direction only so as to force the tube properly into contact with the web and its coating.

A ith important object of the invention is to provide an improved spreader having an indicator so arranged that tendency of the tube to expand will be properly indicated.

A sixth important object of the invention is to provide an improved spreader which can be readily altered to deposit coatings of diilerent thicknesses upon suitable material.

With the above and other objects in View as will be hereinafter apparent, the invention consists in general of certain novel details of construction and combinations of parts hereinafter fully described, illustrated in the accompanying drawing and specifically claimed.

In the accompanying drawing like characters of reference indicate like parts in the several views, and:

Fig. 1 is a vertical section through a web coating machine constructed in accordance with this invention.

Fig. 2 is a detail horizontal section on the line 2 2 of Fig. 1.

Fig. 3 is a section on the line 3-3 of Fig. 1 to an enlarged scale.

Fig. 4 is a section on the line 4-4 of Fig. 3.

Fig. 5 is a section showing a portion of the machine shown in Fig. 1, the spreader being constructed in accordance with a diierent embodiment of my invention.

In the present embodiment of the invention there is disclosed a V-shaped trough or vat 10 having a drain plug 11 at the bottom. Along one edge of this vat runs a guide roller 12 and in the vat below the surface of the coating material is a second roller 13. Extending above the vat is a frame having legs 14 and a cross member 15. It is to be understood that there is one of these frames at each end of the vat though only one is deemed necessary here to be shown. Resting on the member 15 is a pair of cylinders 16 and 1'? each or' which is provided with a ed longitudinal slot, these cylinders being so arranged that the slots confront each other. These cylinders are held in position by saddle bolts 19. The slot in onecylinder 16 is shown at 1S. Extending longitudinally of this cylinder is a '1e spiral spring member 2G the outside diameter of which is less than the inside diameter of the cylinder but is greater than the width of the slot 18. This member 20 is so positioned in the cylinder that it partly projects through the slot 18. In order to hold the spring in this projected position there is provided in cylinder 16 a strip 21 of some suitable elastic material such as sponge rubber and, in order to prevent wear by direct contact of the springs on this sponge se rubber, there is provided between each strip of rubber and its spring a bearing or wear plate 22 of some suitable metal.

The diameter of the wire, of which the spring member 20 is made, controls the thickness of the deposit of dope upon the strip material. By providing a series of different springs 20 which are constructed of wire of varying diameters, it is an easy matter to select the proper spring for the work in hand as the smaller the diameter of the wire is, the smaller the amount of dope spread upon the material W. Where a Very line wire spring is used the interstices between the spring convolutions admit the passage of only very small quantities of dope. Wire of large diameter will provide much larger interstices between the spring convolutions and will pass considerably more dope.

In place of the elastic means shown in Figs. 1 and 2 for pressing the coil spring 20 through the opening in the tubular member 16, I may use the device shown in Fig. 5 wherein the coil spring 20 may be thrust outwardly by means of a pneumatic tube 221 to which air may be admitted through a nozzle 222 which is normally 105 covered by a cap 229. In this embodiment of my invention the plate 22 may be omitted as also is the sponge rubber 21.

In the construction of the cylinder 17 as here shown there is provided a metallic tube 24 closed 110 its Cil

at one end as at 25. One side of this cylinder is flattened as at 26 and in this flattened side is formed a longitudinal slot 23. Mounted within the tube is a pneumatic tube 2'7 having its inner end closed as at 28 and its outer end likewise closed and provided with a filling valve 29 of the usual type employed in connection with automobile tubes and the like. This valve is arranged at the open end of the tube 24 so that it is convenient for access.

At the top of the tube 24 there is provided an orifice or opening 30 and adjacent this orice is a bracket 3l having a lever 32 pivoted at one end thereto. This lever 32 extends across the opening 30 and at the opening is provided with a projection 33, the free end of the lever running along the tube to form a pointer or index nger.

When the pneumatic tube is blown up it will be observed that it bulges out through the slot 23 as at 34 and at the same time a small portion of the tube will bulge up into the orifice 30 as at 35. it is intended that the orifice 30 and slot 23 shall be so related in size that when the proper bulge is obtained on the tube at 25 the index finger formed by the lever 22 will be substantially parallel to the tube 24. By this means the pressure between the tube is used to indicate the tendency to bulge on the part 34.

In using the invention a suitable quantity of coating material of any desired kind is placed in the vat as indicated at C. The web is then fed ofi a suitable roll, not shown, as indicated at W, passing over the roller 12, under the roller 13 and up between the cylinders just described. As the web passes through the coating the latter adheres thereto and as it passes up between the cylinders these cylinders distribute the coating evenly but with a wavy surface on one side, the advantage being that while the coating is evenly distributed it is not all rubbed off while very fresh as would be the case with an ordinary pair of rubbing elements both having smooth surfaces.

There has thus been provided a simple and eiijcient device of the kind described and for the purpose specified.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, therefore, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

Having thus described the invention, what is claimed as new, is:

l. In a web coating machine, a coating spreader including a hollow cylinder having a longitudinally extending slot, a flexible spiral spring mounted within the cylinder and having a portion projecting through the slot flexibly to engage a freshly coated web and spread the coating thereover, said spring being of less diameter than the internal diameter of the cylinder, and pneumatic means urging the spring outwardly to hold it projecting through the slot.

2. In a coating machine the combination of two opposite co-operating members between which a web may be passed, one of said members being a flexible spiral spring member and the other a smooth wiper element, both members being flexible and adapted to conform to the opposite surfaces of the web.

3. In a web coating machine the combination with a flexible spiral spring member and a pneumatic means adapted to press said spring mem ber against the web to conform to the surface thereof, of a second pneumatic means located opposite said spiral spring member and adapted to present a smooth surface to said web.

4. In a web coating machine the combination with a spreader including a cylinder provided with a longitudinal slot and a pneumatic tube within said cylinder adapted to bulge through said slot into contact with the web, of a second spreader including a cylinder provided with a longitudinal slot, a flexible Spiral spring within said cylinder and having a portion protruding through said slot and a pneumatic tube within said cylinder and adapted to exert a pressure v on said spring.

5. A spreader for a web coating machine comprising a cylinder provided with a longitudinal slot, a flexible spiral spring internally unsupported within said cylinder and having a por- A tion flexibly protruding through said sloJ and a pneumatic means within said cylinder adapted to be inflated and to exert a pressure on said spring.

FREDERICK COATES. 

